European Geosciences Union, Atmospheric Chemistry and Physics, 2(12), p. 869-877, 2012
European Geosciences Union, Atmospheric Chemistry and Physics Discussions, 9(11), p. 25967-25989
DOI: 10.5194/acpd-11-25967-2011
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We examined the influence of the North Atlantic Oscillation (NAO) on the atmospheric dispersion of pollution by computing the emission, transport and removal of insoluble gaseous and water-soluble aerosol tracers, tagged by the continent of origin. We simulated a period of 50 yr (1960-2010), using the ECHAM/MESSy atmospheric chemistry (EMAC) general circulation model. The model accounts for anthropogenic, biogenic and biomass burning sources, removal of trace gases through OH oxidation, and precipitation, sedimentation and deposition of aerosols. The model is shown to reproduce the observed spatial features of the NAO, moisture transports and precipitation. During high NAO phase seasons the axis of maximum westerly North American trace gas transports extends relatively far to the north and east over Europe. The NAO phase is significantly correlated with North American tracer concentrations over the northwestern Atlantic Ocean and across northern Europe, and with European trace gases and aerosols beyond the arctic circle. Our results indicate marked differences and partly reversed correlations for the insoluble gas and the soluble aerosol tracers. We find a strong anti-correlation over western and central Europe between European pollutant gas and aerosol concentrations and the phase of the NAO.